Now the 3DS system firmware has been updated to the 10.6.0-31 for the following regions: USA, EUR, JPN, CHN, KOR, and TWN.

Here is the official USA change-log:

Further improvements to overall system stability and other minor adjustments have been made to enhance the user experience

3DS firmware version 10.6 just came out. it blocks menuhax and browserhax , so i recommend that you do not update if you're on 10.5 ! Ninjhax/oot3dhax should be fine once i update the payloads. Is it block any 3ds flashcart and ds flashcart ?

It has been confirmed that the sky3ds plus flashcart can support the latest 3DS 10.6.0-31 . Other flashcarts like the r4i gold 3ds flashcart ,r4i-sdhc rts flashcart also can support the latest 3DS 10.6.0-31 directly !